docs: def _dump(self, tree):
          """ Run a DUMP statement """
          schema = []
          if tree.tables:
              for table in tree.tables:
                  desc = self.describe(table, refresh=True, require=True)
                  schema.append(desc.schema)
          else:
              for table in self.describe_all():
                  schema.append(table.schema)
  
          return "\n\n".join(schema)